But with the fishers, the behavioral change in the anthropause happened waaaaay too fast to be genetic. Instead, it could be a change driven by choices made by individuals or groups of animals. “You see that personalities differ,” says Wikelski. “There may be now a selection for certain personalities to enter cities, and that may be propagated through their culture.”
“The global experiment on the transmission and retention of information in animal societies is just unbelievably beautiful,” Wikelski adds.
Scientists can watch such rapid, dramatic behavioral shifts thanks to increasingly sophisticated monitoring equipment. Tracking collars of course map an animal’s movement, but some now come equipped with inertial measurement units, or IMUs, the same sensors that let you shift your phone around to control a game. This allows researchers to determine if a wild animal has suddenly accelerated, indicating that it might have been startled. An even more sophisticated monitoring device might detect the animal’s heart rate or listen with a microphone to its interactions with its peers.
“It’s the Fitbit for animals,” says Wikelski. “Are they sick? Are they fine? Are they interacting? How quickly are they moving? Are they getting up at the right time, at the same time as before? Are they active differently during the night, during the day?”
During the anthropause, researchers can marry this data that tracks animal behavior with data that tracks human behavior, particularly traffic, to show whether a species might be exploiting our absence or going about its business as usual in the wild. As the anthropause continues and eventually wanes, scientists will be able to watch how a species adapts, answering questions that would have been impossible to tackle if not for the pandemic.
Researchers have been trying to solve one of these riddles for decades: Are animals afraid of our built environment—roads, buildings, and other infrastructure—or are they afraid of us? “We suddenly didn’t have humans in many areas,” says ecologist Matthias-Claudio Loretto of the Max Planck Institute of Animal Behavior and University of Konstanz, coauthor on the anthropause paper. So, he says, if animals will visit these places during the pandemic shutdown, “they’re obviously just normally afraid of humans.”
On the other hand, if a particular species didn’t penetrate a populated area even with humans gone these past few months, that might be an indication that it’s the built environment keeping them away. But conservation biologists can look at the species that did traipse through an area and note the paths they took.
The riddle gets more nuanced in urban places where the restrictions on movement haven’t been particularly strict. Maybe a city has allowed residents to go for walks, so animals are still avoiding public parks, but are instead turning up in places that are entirely shut down to people. Some cities may have restricted driving, while others didn’t—researchers can look at both traffic and animal data to see how species in different areas adapted.
The anthropause is bringing scientists a unique opportunity to study how animals move through built environments; this knowledge could inform new modifications to urban areas to provide safe passage for animals. For example, maybe if we learn that a development or freeway has sliced a species’ habitat and population in two, we could reunite them to encourage genetic diversity—isolated populations, after all, tend to inbreed. “It’s not good enough that managers tell animals where to go,” says Wikelski. “Animals should tell us where they need to go, where they want to go. It’s the animal-defined corridor that we need.”
But not every animal species has benefited from the freedom of having fewer humans around. The generalists among them, like coyotes, rats, and wild boar, may comfortably move about city streets, taking any food they can. But there’s nothing for a mountain lion in downtown San Francisco—its prey, like deer, remain in the hilly regions to the south of the city.